Drinking Risk

A woman's drinking habits can affect her risk of breast cancer. During a 28-year study of 105,986 women, about 7 percent were diagnosed with the disease. Compared with abstainers, women who averaged three to five drinks per week between ages 18 and 40 had a 13 percent increased risk; when they averaged six to ten drinks weekly, they had a 25 percent increased risk. But a short period of heavy drinking should have little impact on risk as long as one's lifetime drinking average is low, says lead author Wendy Chen, an assistant professor of medicine at Harvard Medical School. Other studies indicate that alcohol increases the body's levels of estrogen, which can contribute to development of the disease.